Mold drying oven



June 23, 1959 4J, M BEYVL 2,891,319

' MOLD DRYING OVEN Filed May e, 1954 ATTORNEY- 2,891,319 Patented une 23, 1,959

Unified States Patent one@ 2,891,319 MOLD DRYING OVEN Joseph M. Beyvl, ClevelandHeghts, Ohio, assgnor to The Foundry Equipment Company, Cleveland, Ohio, a corporation of Ohio Application May 6, 1954, Serial No. 428,029 2 Claims. (Cl. 34-21) This invention relates as indicated to a novel mold drying oven, and more particularly to an improved oven and method for drying molds for ingot molds.

Pit type ovens are well known for the drying of molds for ingot molds, the heated air being circulated through the oven. It is also known to place perforated covers on individual ingot molds standing on a floor or platform and to introduce the heated gases at the underside of the mold with a portion of such gases escaping through the perforated cover plate. The latter arrangement, however, makes for quite uncomfortable and unhealthful working condi-tions in the foundry.

Furthermore, difficulties are encountered n obtaining thorough and uniform drying of the mold cheeks and it is important to ensure flow of the heated air as uni formly as possible across the surfaces to be dried. It is further desirable that the exterior of the mold flask should not be unnecessarily chilled during the drying operation.

It is accordingly a principal object of my invention to provide a novel method of drying ingot molds and the like whereby such molds may be dried in a rapid and uniform manner, without escape of noxious gases, and without damage to` the mold due to sudden or uneven cooling.

Another object is to provide such method which will be unusually elcient in the conservation of heat.

A further object is to provide a mold drying oven adapted to receive the entire ask and mold, and including special provision for circulation of heated gases within the interior of the mold enclosed in such oven.

Other objects of the invention will appear as the description proceeds.

To the accomplishment of the foregoing and related ends, said invention then comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawing setting forth in detail certain illustrative embodiments Vof the invention, these being indicative, however, of but a few of the various ways in which the principle of the invention may be employed.

In said annexed drawing:

Fig. l is a top plan view of a pit type drying oven for ingot mold cheeks;

Fig. 2 is a vertical transverse section taken on the line 2-2 on Fig l; and

Fig. 3 is a vertical longitudinal section taken on the line 3-3 on Fig. 2.

Referring now more particularly to such drawing, air is drawn into burner 1 through inlet 2 and then forced by heat supply fan 3 into duct 4 which extends the length of the elongated pit type oven 5. Insulated covers 6 provided with lifting hooks 7 have longitudinally extending downturned side flanges 8 received in troughs or channels 9 which may, if desired, be lled with water .to afford and improved seal.

Rails 10 and 11 extend longitudinally within the oven lon lateral ledges therein and are adapted to support the usual molds 12. Such molds are provided with covers 13, either perforate or imperforate but `preferably thelatter. v

Return ducts 14 and 15 communicate with the lower portion of the pit type oven 5 to either side of duct 4 but do not extend any substantial distance into the oven. An exhaust fan 16 is operative to withdraw a `portion of the semi-saturated heated gases returning from the oven through such exhaust ducts and to deliver the same to the stack 17. The larger portion of the returning gases will, however, be drawn through duct 18 to burner 1 where it will be reheated and recirculated through the action of fan 3.

A plurality of equally spaced nozzles 19 lead upwardly from duct 4 and are located centrally of the respective covers 6 in order that they may direct the heated air upwardly into the respective molds 12 resting on rails 10 and 11.

In operation, the several molds are transported by crane and lowered into position on rails 10 and 11, whereupon the covers 13 and 6 are put in place. The heated gases directed upwardly from nozzles 19 will impinge against cover plates 13 and then llow generally downwardly with a certain amount of turbulence along the mold cheeks. The partially saturated gases escaping from the bottom of the molds will be withdrawn through exhaust ducts 14 and 15 and since such molds are ordinarily round, a certain proportion of the gases may pass upwardly between the molds and flow about the exteriors of the same. Of course, if cover plates 13 are perforate, a larger proportion of the partly saturated heated gases will pass into the region between the mold flasks and the oven walls, thereby raising the temperature of the entire oven and its contents to an appreciable degree. It will thus be seen that while the mold is entirely enclosed within an oven, it serves itself also as an oven since each mold is provided with its own individual hot air inlet nozzle. This arrangement substantially eliminates the leakage of gases to the outeratmosphere as generally takes place when heated gases are circulated within a mold and the individual mold cover is relied upon to prevent escape of the same. My new oven is relatively simple in construction and operation and produces molds which are uniformly dried in a relatively short period of time.

By positioning the nozzles centrally of the lower openings of the respective molds a uniform distribution of the heated gases is obtained, with such gases descending within the mold and being withdrawn laterally circumferentially of such nozzles.

Other modes of applying the principle of the invention may I therefore particularly as my invention:

1. The method of drying molds for ingot molds which comprises placing the same in an enclosed pit type oven, placing covers on the upper ends of the individual molds, continuously introducing heated gases under pressure upwardly into such molds, circulating such gases uniformly around the molds over the exterior thereof, continuously withdrawing such gases from the lower ends of such molds and withdrawing such gases from said enclosed pit at one end thereof symmetrically with respect to a cross-section of said pit oven, discharging a portion of such withdrawn gases, and reheating and recirculating the remainder together with make-up equal to that discharged.

2. In a mold drying system including a pit type oven and covers therefor, an inlet duct extending along the point out and distinctly claim bottom of said pit, spaced upwardly projecting nozzles leading .from Lsaid duct, .supports lfor molds within -sad pit adapted to support such molds over individual nozzles for introduction of heated gases, said supports affording LIclearance for ldownward Withdrawal fof such gases Vfrom such molds" laterally tof fsaid nozzles,l a Vreturn duct communicating with one end .of said oven, 'a :fan 'operative to divert va portion of v'the Withdrawn gases :from `said return duct and to discharge them to atmosphere, va heater, antl'alblower operative to draw the balance of su'ch Withdrawn gases through said heater for recirculation to said inlet duct.

References Cited in the le of this patent UNITED STATES PATENTS Merchant Mar. 13, 1894 Anthony Dec. 23, 1919 Vergniaud Apr. 5, 1921 Barnett etal Nov. 9, 1948 Mayer May 30, 1950 Beyv1. Sept. 3, 1957 FOREIGN Y GreatBritain Apr. 21, 195 

